A very interesting article, I have personal experience with:

> Coffee also affects the gastrointestinal tract. It increases stomach acidity and stimulates the release of hormones that aid digestion. Both caffeinated and decaffeinated coffee promote the contractility of ileal and colonic smooth muscle, helping prevent constipation

As the two times in my adult life I've tried to make an intended break from coffee, it has ended up with almost unbearable stomach pain caused by constipation.

It's good to know that this is not linked to caffeine as I thought, so I will try un-caffinated coffee instead now because I tend to think that my general "tiredness" comes from actual caffeine.

After habitually consuming caffeine (not in coffee form) daily, usually multiple times a day, for more than a decade, a horrible mental health incident happened to me that forced me to stop it for a while. Afterwards I didn't resume the habit, and so I no longer have a tolerance.

This has let me evaluate what caffeine does with fresh eyes, so to say, because I can now consume it occasionally while having many non-caffeinated days to compare to. It's a profoundly psychoactive substance and does a lot of things to cognition. I guess I have decided I don't enjoy how it feels, having previously been dependent on it.

Here is a fun citation with a brief summary. They suggest regular caffine use lowers your baseline and it just returns you to where you'd be if you weren't dependent.

University of Bristol. "Coffee consumption unrelated to alertness: Stimulating effects may be illusion, study finds." ScienceDaily. ScienceDaily, 3 June 2010. <www.sciencedaily.com/releases/2010/06/100602211940.htm>.

Funded by the Institute for Scientific Information on Coffee (ISIC) — an industry body — which is a notable conflict of interest the authors disclose but don't extensively discuss

thirty-one participants were moderate coffee-drinkers (CD, i.e., people that usually consume between 3 to 5 cups of coffee per day).

3-5 is moderate? To me, 3 is already high.

Also, sample size is pretty low and they're all Irish.

Was this thread invaded by AI? Casually reading the first comments, 3 different users mentioned they had a recent "mental health incident" related to caffeine??

Search this page for "mental health incident"

I’m super interested in this sort of study! However, it looks like n=62 here, which I think weakens the results —they’re probably just useful as suggestions of possible effects. Also, any food is expected to have similar effects on the microbiome. They didn’t test caffeine in isolation. In some ways that’s better (I don’t consume caffeine in isolation), but in some ways that’s less useful (it’s possible you get similar results from many random vegetables)

I switched from caffeine (coffee) to theacrine (pills) and I like it so much more. I feel alert and focused without added anxiety. It doesn’t seem to affect my sleep at all. I really didn’t like how hard it was to quit coffee.

I don’t like that it’s a pill. I tried making my own theacrine drinks, but theacrine is so bitter that I never found one that I liked. I am still haunted by the chicory + theacrine drink I made…

It would have been interesting to see if there was any difference relating to CYP1A2 (Cytochrome P450 1A2), the fast metabolizers and the slow metabolizers.

What's cool is this effect exists even in decaf coffee, as someone who primarily drinks decaf black, for flavor and for a good night's rest as I'm sensitive to caffeine.

Caffeine is an extremely potent drug.

It’s actually kind of crazy to think that a large portion of a country’s population could be “high” on it basically all of the time. And there is a huge industry in place for delivering said drug to as many people as possible by having it available on almost every street corner.

And that most people take a fairly non-chalant attitude to giving this drug to kids through sweet drinks that are primarily marketed to them as well.

The scale of it is kinda mind boggling to me.

Mind the nonsensical rant, I haven’t had my coffee yet this morning…

I am not a coffee drinker, but I met with a friend at a cafe who said he was going to get a cup of insect poison, referring to coffee :)

> The coffee provided was consumed with a quantity of hot water, milk, sugar chosen by the participant.

Could it be the sugar?

At least subjectively, coffee seems to help my memory. But maybe that's why I started drinking coffee?

I would probably drop coffee it was proven to have negative effects on memory.

I have not much followed the science of gut microbiome and psychology. Is this really going where this article is pointing? That we can tease out causation in foods and habits via gut microbiome towards behavior and psychology? Pretty rad.

Coffee modifies physiology and cognition? You're telling me this for the first time.

Would be real interesting to see a similar study on tea.

I must be weird, but coffee (or caffeine) doesn’t really “wake me up” in the mornings and I could drink it in the night and still sleep well. Because of that I don’t drink coffee; I prefer tea

Whatever the case, a cup of coffee is basically what kickstarts my day.

good thing I have claude to summarize this and quickly realized that sample size was small and nothing much new unless you are a microbiome researcher

Yes, well, nevertheless. Sip

I only use caffeine or caffeinated beverages such as coffee at the most three times a week. And that's a heavy week for me.

> ... reintroduction triggered acute microbiome changes independent of caffeine.

This sounds interesting. I've never really considered the constituents of coffee other than caffeine and what unique effects they may bring.

I wonder if I would experience behavioral effects if I replaced my coffee intake with caffeinated non-coffee drinks or pills?

The only good thing that keeps me from collapsing into a state of limbo is coffee and now, even that's bad (seems more like a mixed bag, but still)? Sigh.

"These findings reveal previously unrecognised effects of coffee on the microbiota–gut–brain axis, suggesting that microbiome profiles could potentially predict coffee consumption patterns", or, perhaps, just ask the patient?